GATE 2024 EC – Question 23
In the circuit shown, the $n:1$ step-down transformer and the diodes are ideal. The diodes have no voltage drop in forward biased condition. If the input voltage (in Volts) is $V_s(t)=10\sin\omega t$ and the average value of load voltage $V_L(t)$ (in Volts) is $2.5/\pi$, the value of $n$ is ______.
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Correct answer: (B) 8
Explanation
This is a centre-tapped full-wave rectifier. Each half of the secondary delivers a peak of $10/n$ V, and the average of the full-wave rectified output is $\dfrac{2}{\pi}\cdot\dfrac{10}{n}=\dfrac{20}{n\pi}$. Setting $\dfrac{20}{n\pi}=\dfrac{2.5}{\pi}$ gives $n=8$.